Conventionally, as sliders used for slide fasteners, there is known a slider having an automatic stop mechanism, in which when operation of a pull tab is stopped after a slide fastener is opened or closed, a locking pawl mounted on the slider is automatically operated to keep the slider at a stopped position and also such a sliding-stopped state of the slider can be kept as far as the pull tab is no longer operated. Also, a specific example of the slider having such an automatic stop mechanism is disclosed from Japanese Patent Application Publication No. 2013-31691 (Patent Document 1) and the like.
For example, a slider disclosed from Patent Document 1 is provided, on an upper blade thereof, with an insertion groove allowing a locking pawl to be inserted therein, a pawl hole provided on a rear mouth-side end edge portion of the upper blade to extend from an upper surface of the upper blade to an element guide passage, crimping protrusions erected on both right and left sides of the insertion groove in a front end portion of the upper blade, and right and left pull tab holding portions for holding a pull tab.
Also, the locking pawl according to Patent Document 1 has a pawl portion arranged on one end of the locking pawl to be inserted through the pawl hole of the slider body, a hook portion arranged on the other end of the locking pawl to be fitted into the insertion groove of the slider body, and a cover portion provided between the pawl portion and the hook portion to cover a connection rod of the pull tab.
In addition, the pull tab of Patent Document 1 have has a pull tab body, right and left arm portions provided to extend from the pull tab body, and a circular columnar-shaped connection rod connecting leading ends of the right and left arm portions. Also, in the middle of the connection rod in a right and left direction, a recessed portion is formed to cause a cross section of the connection rod to become a half circular shape.
Also, in Patent Document 1, when the pull tab and the locking pawl as described above are mounted on the slider body, the connection rod of the pull tab is first inserted into the pull tab holding portions and then the pull tab holding portions are crimped, thereby pivotally holding the pull tab on the slider body. Subsequently, the locking pawl is inserted into the insertion groove of the slider body with the pull tab held thereon, while being positioned to allow the pawl portion to be inserted though the pawl hole of the slider body. Therefore, the locking pawl is positioned at a predetermined position on the slider body.
Then, by crimping the protrusions of the slider body, the other end of the locking pawl is fixed in a crimping manner while having a predetermined clearance. In this way, the slider of Patent Document 1 is assembled.
In the case of the slider of Patent Document 1 assembled as described above, when the pull tab is laid down toward the rear mouth, the cover portion of the locking pawl is fitted into the recessed portion of the pull tab, and a position of the locking pawl relative to the slider body descends. Accordingly, the pawl portion of the locking pawl is inserted into the element guide passage though the pawl hole of the slider body.
Contrarily, when the pull tab is stood up or laid down toward the front end side of the slider, the cover portion of the locking pawl is lifted by pivoting of the connection rod of the pull tab, so that the pawl portion of the locking pawl is removed from the element guide passage. In this case, the other end of the locking pawl is kept fixed while having the predetermined clearance as described above. Accordingly, when the pull tab is operated to be laid down or stood up, the other end of the locking pawl is allowed to be moved in the insertion groove due to the clearance, and thus operations of inserting and removing the pawl portion into and from the element guide passage can be smoothly performed.
Therefore, when a slide fastener is constructed using the slider, for example, if operation of the pull tab is stopped and then the pull tab is laid down toward the rear mouth, the pawl portion of the locking pawl can protrude into the element guide passage and thus can be engaged with element rows. Accordingly, the slider is stopped relative to the element rows and also the stopped position can be kept. Contrarily, if the pull tab is stood up for the purpose of operating the slider, the pawl portion is removed from the element guide passage and thus the pawl portion and the element rows are disengaged, thereby allowing the slider to be smoothly slid along the element rows.